In law, a conviction is the verdict that usually results when a court of law finds a defendantguilty of a crime.[1] The opposite of a conviction is an acquittal (that is, "not guilty"). In Scotland and in the Netherlands, there can also be a verdict of "not proven", which counts as an acquittal. There are also cases in which the court orders that a defendant not be convicted, despite being found guilty; in England, Wales, Canada, Australia, and New Zealand the mechanism for this is a discharge.

For a host of reasons, the criminal justice system is not perfect: sometimes guilty defendants are acquitted, while innocent people are convicted. Appeal mechanisms and post conviction relief procedures may mitigate the effects of a conviction to some extent. An error which results in the conviction of an innocent person is known as a miscarriage of justice.

A minor conviction is a warning conviction, and it does not affect the defendant but does serve as a warning.[citation needed]

A history of convictions are called antecedents, known colloquially as "previous" in the United Kingdom, and "priors" in the United States and Australia. The history of convictions also shows that a minor law conviction can be prosecuted as any individual's punishment.